Other Assets- Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Feb. 23, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Business Combination Contingent Consideration Asset	$ 0		$ 0			$ 0
PUERTO RICO
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	(542,706,000)	$ (7,211,000)	(537,067,000)	$ (14,183,000)
PUERTO RICO | Westernbank Assets Capital Gain Treatment [Member] | Closing Agreement with the Puerto Rico Department of Treasury [Member]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Income Taxes Paid			$ 45,000,000
UNITED STATES
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Income Tax Reconciliation, Change in Deferred Tax Assets Valuation Allowance	$ 544,900,000
Banco Popular De Puerto Rico [Member] | FDIC Assisted Partial Acquisition Of Doral Bank [Member]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement					$ 5,000,000,000